/* Copyright (C) 2004 Viktor T. Toth <http://www.vttoth.com/>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be
 * useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 * PURPOSE.  See the GNU General Public License for more details.
 *
 * The main MAXIMA tensor demo
 *
 */

done,
block(
[sel:false],
print("This is the main demonstration program for MAXIMA tensors."),
print("The following demos are available:"),
while sel#x and sel#X do
(
/* This block of code restores trigonometric
   simplification properties that are removed
   when a kill(all) is executed. */
  kill(all),
  put('sin,'cos,'complement_function),
  put('cos,'sin,'complement_function),
  put('sinh,'cosh,'complement_function),
  put('cosh,'sinh,'complement_function),
  put('cos,1,'unitcof),
  put('sin,1,'unitcof),
  put('cosh,1,'unitcof),
  put('sinh,-1,'unitcof),
  put('cos,-1,'complement_cof),
  put('sin,-1,'complement_cof),
  put('cosh,1,'complement_cof),
  put('sinh,1,'complement_cof),
  put('sin,'trigonometric,'type),
  put('cos,'trigonometric,'type),
  put('sinh,'hyper_trigonometric,'type),
  put('cosh,'hyper_trigonometric,'type),
print(""),
print("INDICIAL TENSOR MANIPULATION        COMPONENT TENSOR MANIPULATION"),
print("1. Basics                           11. Initialization"),
print("2. Index contraction                12. Differential geometry"),
print("3. Simplification and symmetries    13. Gravitational theory"),
print("4. Special tensors                  14. Frame fields"),
print("5. Coordinate differentiation       15. Torsion and nonmetricity"),
print("6. Covariant derivatives, curvature 16. Algebraic classification"),
print("7. Exterior algebra                 17. Differential equations"),
print("8. Generating CTENSOR programs      18. Using Taylor series"),
print("9. Frames, torsion, nonmetricity"),
print(""),
print("A. Algebraic tensor manipulation"),
print("E. Complete examples"),
print("X. Exit this demo"),
print(""),
sel:read("Select an option by its number followed by a semicolon (;)"),
    if sel=1 then demo(itensor1)
   else if sel=2 then demo(itensor2)
   else if sel=3 then demo(itensor3)
   else if sel=4 then demo(itensor4)
   else if sel=5 then demo(itensor5)
   else if sel=6 then demo(itensor6)
   else if sel=7 then demo(ex_calc)
   else if sel=8 then demo(itensor8)
   else if sel=9 then demo(itensor9)
   else if sel=11 then demo(ctensor1)
   else if sel=12 then demo(ctensor2)
   else if sel=13 then demo(ctensor3)
   else if sel=14 then demo(ctensor4)
   else if sel=15 then demo(ctensor5)
   else if sel=16 then demo(ctensor6)
   else if sel=17 then demo(ctensor7)
   else if sel=18 then demo(ctensor8)
   else if sel=a then demo(atensor)
   else if sel=E or sel=e then
(
print("The following specific examples demonstrate practical applications:"),
print(""),
print("INDICIAL TENSOR MANIPULATION        COMPONENT TENSOR MANIPULATION"),
print("1. Proving the Bianchi-identities   11. Deriving Schwarzschild's metric"),
print("2. Proving Cartan's identities      12. Verifying Reissner-Nordstrom"),
print("3. The Kaluza-Klein metric          13. Petrov classification of metrics"),
print("4. The double divergence of R       14. Using a tetrad base"),
print("5. Helicity in hydrodynamics        15. The Friedmann equations"),
print("6. Magnetic field in plasma         16. Papapetrou's nonsymmetric metric"),
print("7. Spinor algebra                   17. The Kruskal extension"),
print("8. The EM field tensor              18. Hydrostatic equilibrium"),
print("9. The Hodge star operator"),
print("A. The Riemann and Weyl tensors"),
print("B. The Rainich conditions"),
print("C. The Einstein-Hilbert action"),
print("D. Brans-Dicke cosmology"),
print(""),
print("X. Return to main menu"),
print(""),
sel:read("Select an option by its number followed by a semicolon (;)"),
    if sel=1 then demo(bianchi)
   else if sel=2 then demo(car_iden)
   else if sel=3 then demo(kaluza)
   else if sel=4 then demo(ademo)
   else if sel=5 then demo(helicity)
   else if sel=6 then demo(plasma)
   else if sel=7 then demo(spinor)
   else if sel=8 then demo(maxwell)
   else if sel=9 then demo(hodge)
   else if sel=a or sel=A then demo(weyl)
   else if sel=b or sel=B then demo(rainich)
   else if sel=c or sel=C then demo(einhil)
   else if sel=d or sel=D then demo(bradic)
   else if sel=11 then demo(schwarz)
   else if sel=12 then demo(reissner)
   else if sel=13 then
   (
     print("Choose from the following metrics"),
     print(""),
     print("1. The Schwarschild metric (type D)"),
     print("2. The Kerr metric (type D)"),
     print("3. The anti-deSitter metric (type 0)"),
     print("4. Godel's universe (type D)"),
     print("5. Taub-Nut plane vacuum (type D)"),
     print("6. Allnutt's perfect fluid metric (type III)"),
     print(""),
     print("X. Return to main menu"),
     print(""),
     sel:read("Select an option by its number followed by a semicolon (;)"),
      if sel=1 then demo("ctensor6")
     else if sel=2 then demo("petrov")
     else if sel=3 then demo("adsitter")
     else if sel=4 then demo("godel")
     else if sel=5 then demo("taubnut")
     else if sel=6 then demo("allnutt")
     else if sel#X and sel#x then print("*** Invalid entry, please try again")
     else sel:0
   )
   else if sel=14 then demo(tetrad)
   else if sel=15 then demo(friedmann)
   else if sel=16 then demo(papapetrou)
   else if sel=17 then demo(kruskal)
   else if sel=18 then demo(hydro)
   else if sel#X and sel#x then print("*** Invalid entry, please try again")
   else sel:0
)
   else if sel#X and sel#x then print("*** Invalid entry, please try again")
))$